1. Field of the Invention
The present invention relates generally to bicycle suspension systems. In particular, the present invention relates to shock absorbers and suspension assemblies suitable for use in connection with off-road bicycles.
2. Description of the Related Art
Off-road bicycles, or mountain bikes, may be equipped with front and rear suspension assemblies operably positioned between the frame of the bicycle and the front and rear wheels, respectively. Providing front and rear suspension on a mountain bike potentially improves handling and performance by absorbing bumps, and other rough trail conditions, which may be encountered while riding off-road. However, because mountain bikes are typically pedal-driven, i.e., use the rider's power output to propel the bicycle, the provision of rear suspension, especially, may undesirably absorb a rider's power output, resulting in wasted effort.
Accordingly, rear suspension systems commonly incorporated on engine-driven vehicles, such as motorcycles, have proven undesirable for use with pedal-driven vehicles, such as mountain bikes. In addition, because a mountain bike is propelled solely by power output from the rider, it is desirable that the rear suspension assembly be lightweight. Rear suspension systems of engine-driven vehicles commonly emphasize strength over weight and, therefore, have not been widely incorporated on mountain bikes.
Bicycle shock absorbers having rider-adjustable compression and rebound damping characteristics have been used to match a desired level of pedaling efficiency and ride comfort with a type of terrain encountered. A rider may adjust the compression damping setting of a shock absorber to trade improved pedaling efficiency for improved bump absorption. For example, an adjustable shock absorber may desirably be set to a firm setting while a rider is on a steep hill climb to increase the amount of pedaling energy reaching the driven wheel and reduce the amount of pedaling energy dissipated by the suspension. Conversely, an adjustable shock absorber may desirably be set to a relatively soft compression damping setting where a rider is traveling fast downhill.
In addition, many bicycle shock absorbers have other rider-adjustable settings. For example, some bicycle shock absorbers allow the user to set the sag. Sag refers to the amount of movement experienced by the suspension under just the static load, or body weight, of the rider.
All of these different adjustments can be overwhelming to a user, especially a less experienced rider. Not only do some shock absorbers have multiple adjustments but some adjustments require a specific procedure that can be time consuming and difficult to perform.
For example, to set the sag on currently available air shock absorbers, a specific setup procedure, which can include multiple steps and adjustments, is required to ensure maximum performance. Generally, the rider has to adjust the air pressure and the sag position multiple times to achieve the desired sag when sitting on the bike. This includes measuring the shock absorber, filling the shock with air, sitting on the bike, measuring the sag, letting air out of the shock or adding more air, getting back on the bike, and measuring the sag again. These steps are repeated until the sag is set to the desired position.
The desired sag position may be given in a chart in a user manual and indicated as a length or a sag percentage based on the particular shock and the rider's weight among other factors. This can further complicate the procedure.
Because of the perceived difficultly of certain, if not all of the adjustments, some riders may have the shock absorber adjusted or set-up when it is originally purchased and then make no further adjustments. In addition, certain bike shops or consumers may not make all of the right adjustments. This may be in order to save time or just because of lack of understanding of the correct procedure and settings.
Accordingly, a need exists for a shock absorber that simplifies at least some of the adjustment procedures.